Hi @Hellv,
The whole branch will be selected if you click Select->All in the property bar. If you click on individual vertices subsequently, you’ll only select individual vertices. You can hold ctrl to select multiple. You can hit Clear to remove your selection.
You can also use the brush to select multiple. Hold the space bar over your branch to reveal the brush. If you have Soft-selection on, it will select vertices close to the ones you brush over around the whole branch.
If you’re having a different issue, let us know.
I hope this helps!