Yes, it is the same Actress, and no, the first culture was not the Dominion.

Just like this person is not Odo.

And just like this person is not Benjamin Sisko’s Father.

And just like this person is not Weyoun in disguise.

And just like this person is not Tuvok undercover as a terrorist.

I <3 you, Loli.

@Seek
Thanks :)
And of course this is not Lt. Cmdr. Worf.
It is his ancestor, Colonel Worf.

And how could I forget this guy, who is not Tom Paris.

Or this woman, who is not Lt. Tasha Yar.

Or this man, who is not Gul Dukat.

Or this one, who is not the Federation ambassador to Nimbus 3.

And I almost forgot this Romulan, who is not Spock’s father.

…

@Patty_Melt
And then there is this one, who is not an extremely old Nurse Chapel.

And this is not a reincarnated Captain Terrell after he vaporised himself in Star Trek 2.

And this is not an elder Jake Sisko in Klingon disguise.

@ragingloli Also don’t forget the original Number one https://en.wikipedia.org/wiki/Number_One_(Star_Trek)#/media/File:Number_One_Star_Trek.jpg in the pilot is not nurse chapel.