Inputlookup in dropdown to display different columns

[dannili]

Hi all, I'm creating a dashboard that contains drop downs that allow viewers to select a field user_id and the table will display a list of user_ids and other columns' value regarding the id. But due to security issues, I am only given a search index=version_search and when I edit dynamic options in drop downs, search strings return no result.

All information I have now is:
Index general settings:

/home/data/version_search/db

My source file:(pretty sure the inputlookup search_version is not correct because not sure if lookup tables being created)

      <input type="dropdown" token="user_id">
        <label>Select a user ID</label>
        <choice value="*">All</choice>
        <default>*</default>
        <fieldForLabel>user_id</fieldForLabel>
        <fieldForValue>user_id</fieldForValue>
        <search>
          <query>| inputlookup version_search | dedup "user_id" | fields "user_id"</query>
          <earliest>0</earliest>
          <latest></latest>
        </search>
      </input>

Does anyone know any possible solutions? Thanks in advance!