In D&D the See Invisibility spell lets you do exactly what it says; it lets you see invisible creatures as if they were visible.
But in Baldur's Gate 3 it doesn't seem to work that way; it only seems to let you roll to maybe detect them, so it can be a total waste of a spell slot or elixir to use it. I've found it far easier to find invisible creatures by simply throwing around area effects, e.g- bombs.
It's especially annoying because there are particular enemies like Baal cultists and hags that make heavy use of invisibility, and the one thing that's supposed to help you cope with it, doesn't. So it's far easier to become invisible than it is to counteract it? You might say "so just go invisible too then" but that doesn't work, because enemies with invisibility don't seem to have any limits on how long they stay invisible, or how often they can return to being invisible.