Multidropdown

Except of the double "value" this seems good for me. The multiple dropdown will show all selected options like this.

Did you think about using a checkbox field?

no,

i want to show data like this after selecting multiple values

Value is stacked when you are trying to select a value from the component but when it is selected, it will be shown continuously only, without getting stacked. 

That is how the component behaves. 

This looks like a richtextdisplayfield with a bulleted list. While you can display the data like this, I do not know how you want to combine this with the dropdown.

this is how it looks like with below code

Try...

a!localVariables(
  local!list: split("option1;option2;option3", ";"),
  local!selection,
  a!richTextDisplayField(
    value: {
      a!richTextBulletedList(
        items: a!forEach(
          items: local!list,
          expression: a!richTextItem(
            text: fv!item,
            link: a!dynamicLink(
              value: symmetricdifference(fv!item, local!selection),
              saveInto: local!selection
            ),
            linkStyle: "STANDALONE",
            style: if(
              contains(local!selection, fv!item),
              { "UNDERLINE", "STRONG" },
              "PLAIN"
            )
          )
        )
      )
    }
  )
)

Try...

a!localVariables(
  local!list: split("option1;option2;option3", ";"),
  local!selection,
  a!richTextDisplayField(
    value: {
      a!richTextBulletedList(
        items: a!forEach(
          items: local!list,
          expression: a!richTextItem(
            text: fv!item,
            link: a!dynamicLink(
              value: symmetricdifference(fv!item, local!selection),
              saveInto: local!selection
            ),
            linkStyle: "STANDALONE",
            style: if(
              contains(local!selection, fv!item),
              { "UNDERLINE", "STRONG" },
              "PLAIN"
            )
          )
        )
      )
    }
  )
)