Using Flow to create a variable and then use in a 'query'

Hi - I am creating a Flow to do the following:

1. On item modified
2. Initialize variable 'shortnameVar' - set to single line of text field with multiple value 'shortname1' (this field will contain values like ABD DEF)
3. Get Items from another list (in this list are items where 'shortname2' exists but with only one value.
4. Apply to each
5. Output from previous step - Value, with condition of 'shortname2:value' contains 'shortnameVar'.

I am essentially trying to use a list item column that will contain a single entry to query a column that may contain multiple entries to extract only those that evalute to true.

Thanks