Need help creating an interface with navigation pattern to use Interfaces

You can use choose function. Create a local variable and on click of the navigation panel on the left side set the index value to that local variable and use it to show the interface. 

i hope you used foreach loop to show the left panel if not the manually set the index on each tab for the local varibal.

 a!localVariables(
    local!activeNavSection: 1,
    local!navSections: {
      a!map(name: "Workspace", icon: "briefcase"),
      a!map(name: "Tasks",     icon: "tasks"),
      a!map(name: "Requests",  icon: "paper-plane"),
      a!map(name: "Calendar",  icon: "calendar"),
      a!map(name: "My Time",   icon: "clock-o"),
      a!map(name: "Expenses",  icon: "money")
    },
    {
      a!columnsLayout(
        columns: {
          a!columnLayout(
            contents: {
              a!forEach(
                items: local!navSections,
                expression: a!cardLayout(
                  contents: a!sideBySideLayout(
                    items: {
                      a!sideBySideItem(
                        item: a!richTextDisplayField(
                          labelPosition: "COLLAPSED",
                          value: a!richTextIcon(
                            icon: fv!item.icon,
                            color: if(
                              fv!index = local!activeNavSection,
                              "STANDARD",
                              "SECONDARY"
                            ),
                            size: "MEDIUM"
                          ),
                          align: "LEFT"
                        ),
                        width: "MINIMIZE"
                      ),
                      a!sideBySideItem(
                        item: a!richTextDisplayField(
                          labelPosition: "COLLAPSED",
                          value: a!richTextItem(
                            text: fv!item.name,
                            color: "ACCENT",
                            size: "MEDIUM",
                            style: if(
                              fv!index = local!activeNavSection,
                              "STRONG",
                              "PLAIN"
                            )
                          )
                        )
                      )
                    },
                    alignVertical: "MIDDLE"
                  ),
                  link: a!dynamicLink(
                    value: fv!index,
                    saveInto: local!activeNavSection
                  ),
                  style: if(
                    fv!index = local!activeNavSection,
                    "ACCENT",
                    "NONE"
                  ),
                  showBorder: false,
                  accessibilityText: if(
                    fv!index = local!activeNavSection,
                    fv!item.name & " " & "selected",
                    ""
                  )
                )
              ),
              /* This card is used to set a minimum height on the column so that the *
               * divider takes up more screen space when there is minimal content.   *
               * Once content is added to the main column, this can be removed.      */
              a!cardLayout(
                height: "TALL",
                showWhen: not(a!isPageWidth("PHONE")),
                showBorder: false
              )
            },
            width: "NARROW"
          ),
          a!columnLayout(
            contents: {
              choose(
                local!activeNavSection,
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                ),
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                ),
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                ),
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                ),
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                ),
                a!sectionLayout(
                  label: index(
                    local!navSections.name,
                    local!activeNavSection,
                    ""
                  ),
                  contents: {}
                )
              )
            }
          )
        },
        spacing: "SPARSE",
        showDividers: true
      )
    }
  )

Syntax for choose function:

choose(
local!a,
{ rule!Interface_1 },
{ rule!Interface_2 },
{ rule!Interface_3 }
)

Thanks for your quick response. It worked. 

-Suneetha

Your Welcome. 

Your Welcome.