Qlik sense - Customize label on drill-down dimension

I am trying to customize labels on drill-down dimensions and after doing some research this is apparently not possible in frontend? It's a problem when you use hierarchy dimension in drilldown and the field names don't have appropriate labels for the visual object.

Correct, you cannot use expressions to dynamically modify Master Dimension labels. If you're willing to go outside the box, though, you can get clever with If() statements to simulate a drilldown dimension.

Say you had a drilldown dimension that was set up with 3 dimensions in the hierarchy:

What you could do is create a new variable called vDrilldownDim or something like that and use this expression as the definition:

=If( GetPossibleCount(TransLineID) = 1
   , If( GetPossibleCount(TransID) = 1
       , 'Dim1'
       , 'TransID'
      )
    , 'TransLineID'
)

This expression utilizes the GetPossibleCount() function to check whether just 1 value in a given field is Possible to select, at which point it would dynamically "drilldown" to the next field in the expression that has more than 1 value possible to select, which is essentially how a drilldown Master Dimension works, too.

In your chart objects, you can reference the variable in your field like this:

=[$(vDrilldownDim)]

...and in your field label like this:

='$(vDrilldownDim)'

Then the behavior is basically the same as a drilldown Master Dimension but you can modify that field label expression above to be whatever you need it to be, or even create a second variable to handle it.