User-Driven Grid Customization in Appian: How to Hide/Show Columns?

Hi [mention:9596a3623d7444559b7421fd0d9bf267:e9ed411860ed4f2ba0265705b8793d05] ,

I think this might work. Please create the grid with every column and add showWhen condition to every column. Now save the selected columns in a list and with those columns' names, all the showWhen conditions will comply and you will achieve the outcome.

You can take reference from this code snippet 

a!localVariables(
  local!data: {
    a!map(Id: 1, name: "aman", age: 22),
    a!map(Id: 2, name: "aman2", age: 23),
    a!map(Id: 3, name: "aman3", age: 24)
  },
  local!allColumns:{ "Id", "name","age" },
  local!selectedColumn: { "Id", "name" },
  {
    a!multipleDropdownField(
      choiceLabels: local!allColumns,
      choiceValues: local!allColumns,
      label: "show columns",
      labelPosition: "ABOVE",
      saveInto: {local!selectedColumn},
      value: local!selectedColumn,
      searchDisplay: "AUTO",
      validations: {}
    ),
    a!gridField(
      label: "Read-only Grid",
      labelPosition: "ABOVE",
      data: local!data,
      columns: {
        a!gridColumn(
          label: "Id",
          value: fv!row.Id,
          showWhen: contains(local!selectedColumn, "Id")
        ),
        a!gridColumn(
          label: "name",
          value: fv!row.name,
          showWhen: contains(local!selectedColumn, "name")
        ),
        a!gridColumn(
          label: "age",
          value: fv!row.age,
          showWhen: contains(local!selectedColumn, "age")
        )
      },
      validations: {}
    )
  }
)

result 


as You mentioned record action , I'm assuming  you want to store the selected columns in database so that user can see the selected columns even after refreshing the page then you have to store the value in database as per user and if You have multiple grids for multiple records then you can store the value user specific and grid specific for more powerful out come