Hi Jason 
I think this is different from your other app because in the new app you’re using the multiselect dropdown, instead of a repeating group of clickable texts which sets a custom state list. Here, I don’t think you’re able to use the custom state “:plus item” function, because the workflow is “When the multidropdown input is changed” instead of when “This text [inside a repeating group] is clicked”.
However, I don’t think you need the custom state list here because the multidropdown generates the list of Bands for you. Instead of adjusting the workflow, I just changed the repeating group filter to have the User’s list of influential bands contain the Multiselect dropdown list value, instead of a custom state list:
*Note: this expression means that the Users must contain all of the Influential bands in the Multiselect dropdown, not just one of them. For example, if the User selects Opeth and Porcupine Tree, only the Users with Opeth and Porcupine Tree in their list will be displayed in the results.
If you placed a limit such as ‘Select Three Bands’ (change the Maximum Items value from 7 to 3), you could change the filtered expression to:
This way, bands containing any of the three search terms will be displayed in the results (not the entire list).
I haven’t used the multiselect dropdown much in my apps, so there may be some clever workarounds that I’m unfamiliar with, but I think this will show the search results correctly.