It is able to collapse the sequential rows. To collapse rows click on the Switch on/off collapsing main toolbar button:
The triangle and count of sequences in the group will appear near collapsed sequences. Click on the triangle to show the whole tree of the collapsed rows. Also, it is possible to control the collapsed group with a keyboard with a help of Right and Left keyboard arrows.
To update the collapsed groups click on the corresponding main toolbar button.
To sort alignment by collapsed groups use the Sort→ Sort groups, large first or Sort→ Sort groups, small first context menu items.