You posted a TWBX but the data sources are not embedded, they are still live connections, so we can't open it. You'll need to extract all the data sources and re-save the TWBX. To save space you could delete the sheets and data sources that aren't relevant to this question.
My bad on the LIVE connection. I will fix it and here is another question I have and i hope you could help out.
See the picture. These two are exactly the same thing but because the database hasn't been cleaned yet. There become two different parts. How do I combine them into 1?
Ideal result: Google 4
You'll need to create a Group or a Calculated Field from that source field to group the values together.
Groups give you a drag and drop GUI in Desktop but need to be updated when there are new source values.
Calculated Fields are more work but let you handle future cases, e.g.
IF CONTAINS(LOWER([source_field], "goog") THEN "Google"
If your data is even messier you might want to look at Tableau Prep.