Get Filter - 1 specific tag and 2 tags with the highest post counts

I’m trying to create a get filter that will include 1 specific tag and 2 tags (different than the 1 specific) that have the highest post counts. Any idea on how to do this?

For example, if I have these tags (post counts):

  • ORANGE (1)
  • BLUE(8)
  • RED (30)
  • PURPLE (5)
  • GREEN (40)

And I want the ORANGE tag and 2 other tags with the highest post counts, I should get:

  • ORANGE (1)
  • RED (30)
  • GREEN (40)