Regular expression: one character between two characters

I searched a lot, but still could not find the answer to my question, and I am in despair.

I would like to get all the dots (' .') between the brackets, wherever they are, and with and the undefined number of brackets. The problem is that I can just get the first point, but I don’t know how to get everything in one group.

I tried this: \((?:[^\.]*)([\.])(?:[^\.]*)*\)

But it just works if there is only one point. Any idea please?