Daniel 7
5And behold another beast, a second, like to a bear, and it raised up itself on one side, and
it had three ribs in the mouth of it between the teeth of it: and they said thus unto it, Arise, devour much flesh.
This was Medo Persia Empire followed by the Leopard Greece. Already fulfilled.
Rev 13
1And I stood upon the sand of the sea, and saw a beast rise up out of the sea, having seven heads and ten horns, and upon his horns ten crowns, and upon his heads the name of blasphemy.
2And the beast which I saw was like unto a leopard, and his feet were as
the feet of a bear, and his mouth as the mouth of a lion: and the dragon gave him his power, and his seat, and great authority.
3And I saw one of his heads as it were wounded to death; and his deadly wound was healed: and all the world wondered after the beast.
I am weak on Revelation also but if the Bear was Persia in Daniel then it probably is referencing Iran in Rev. The leopard and bear are probably representing nations that have given their power to the Antichrist. Maybe just a general reference to the middle east nations / Persia / bear and the leopard was Greece in Daniel so maybe representative of whatever nations might be descendants of Greece
I am guessing here but using the kinds of guesses that are based on what the angel already told Daniel so if these same references in Rev are intended for us to use Daniel to decipher them (and I think they are) then I think this is the best kind of guessing we can do. Finding a reference in Daniel is a probable meaning. Finding a reference in images on flags, not so much. I don't think applying it to Russia would be what God expected us to get from it. I think he expected us to look at Daniel and think about what the bear represented there.