Keyboard shortcut to open in tab?

Hi.
apologies if I was unclear.
I am not creating a new document. I am combining two existing documents already populated with content.

  1. drag & drop title bar of A onto title bar B to create new tab. Or or Merge All Windows
  2. focus on project in B
  3. click on home in sidebar
  4. A comes into the foreground. Not defocused B
  5. focus on project in A
  6. return to B
  7. click home in sidebar
    8 B is defocused
  8. return to A
  9. click home in sidebar
  10. B is brought to the foreground.

Best

ros