I've done this with a two page dashboard prompt.  The first page is simply a variable prompt called varNameSearch.

The second page column prompt  populates a series of check boxes using SQL and a regular expression to find employee names containing any comma separated values in 'varNameSearch'.

SELECT "People Profile"."Employee Name" FROM "People-Free" WHERE EVALUATE('REGEXP_INSTR(%1,%2)',UPPER("People Profile"."Employee Name"), UPPER(REPLACE('@{varNameSearch}{xxx}',',','|'))) > '0'

This REGEXP returns a count for the number of times it finds any of the values in varNameSearch in a record, so return records  >0.

The UPPER function allows users to enter either upper or lower case values in the first prompt page.

The REPLACE function is replacing any commas in the first prompt with a single pipe "|", which the REGEXP uses as a value separator.

It looks like this:

Select "Apply", then "Next"

It brings up any names with casey or savoy in them:

Check the ones you want, hit Apply, to run your query.