I am looking at this particular guitar tab:
and I am trying to make sense of the notation where you have a triad with the "x" on the top string and the other strings below are in parentheses. Please see the picture.
I believe this is a finger slap but how do you perform a finger slap only on one string and at the same time strum the other two strings? How is this possible at all? Or am I reading it wrong? Could you maybe share a video where this is shown in practice?
This is the song itself:
My screenshot starts at 0:14 sec. It sounds a bit like a finger slap, at the same time like strumming but not exactly. I hope this woukd help in figuring this out.