Complex RANKX with multiple slicers/filters

Hi, Sjoerd_g 

Your model is messy and so are the requirements, it's hard for me to give specific opinions.

For your idea, the reference I can give is that you need to use summarize() in rank() function to customize a context you want, and then sort it. 

If you don't want the line with response < 15 to appear on the visual, you can filter in the filter pane like this:

Measure =
RANKX (
    FILTER (
        SUMMARIZE (
            ALLSELECTED ( sample3 ),
            [Benchmarking],
            [company],
            "Responses", DISTINCTCOUNT ( sample3[response id] ),
            "NPSSOCRE", CALCULATE ( AVERAGE ( sample3[NPS Calc] ), sample3[nps_score] <> BLANK () )
        ),
        [Responses] > 15
    ),
    [NPS score],
    ,
    ,
    DENSE
)

Did I answer your question? Please mark my reply as solution. Thank you very much.
If not, please feel free to ask me.

Best Regards,
Community Support Team _ Janey