Time Ruler green thing

[KKeys88]

Some green and white thing on the time ruler magically appeared and I can't get rid of it.  I am trying to separate out the drums in a MIDI fill and every time I select a track, kick drum, for example, and then select a snare, it jumps to my snare track and I can't delete the snare from my kick drum track.  I think it has something to do with the green thing, whatever it is.  Hope all this makes some sense.

Thank you in advance

[HIBI]

Probably, Selection markers in time ruler?
Whenever a selection exists, the selection range is displayed in the time ruler.
If you need to rid of it, press "Ctrl + Shift + A" to unselect all or just clicking empty part of clips pane.