Populate a dropdown based on a multiple values People field

[RNobleman]

I'm trying to populate a single-select dropdown box with a list of unique names that come from a multiple values People or Groups field in SharePoint. If there's a blank entry, I want to convert it to the text "Unspecified". I also want the dropdown to have an "All People" entry. 

I'm thinking that I need to end up with a table of distinct values for the dropdown, but the source data is in a record format. So how can I convert a record into a table? Can you provide any guidance?

Note: I'll use the dropdown box to filter the results of a gallery.

Thanks.

[RandyHayes · Accepted solution]

@RNobleman 

Use the following formula on the Items property to get what you want:

With({_people:
    ForAll(
        DropColumns(
            GroupBy(
                ShowColumns(
                    Ungroup(
                        YourDataSource.MultiplePersonColumnName,
                        "MultiPerson"
                    ),
                    "DisplayName", "Email"
                ),
                "DisplayName", "Email", "_records"
            ),
            "_records"
        ) As _person,
        Patch(_person, {DisplayName: Coalesce(_person.DisplayName, "Unspecified")})
    )
    },

    Ungroup(
        Table({Items: Table({DisplayName:"All People"})},
              {Items: _people}
        ),
        "Items"
    )
)

Replace YourDataSource.MultiplePersonColumnName in the formula to the name of your datasource and the column name.

I hope this is helpful for you.

[RNobleman]

It worked! Thanks so much for the quick response. 

[RandyHayes]

@RNobleman 

No problem!  Glad it helped!