The meaning of the each are same, but which one is used in what condition?
The meaning is very close between celui-ci and celui-là. In theory, the first one is for things closer than the second one but this nuance is not always respected.
The third one has a different meaning.
They are close to the English: this one (celui-ci) , that one (celui-là) and this (ceci).
You are missing cela / ça for the English that.
Note that celui is masculine singular and must agree with what it refers to, e.g.:
celui-ci - celle-ci - ceux-ci - celles-ci
On the other hand, ceci and cela are invariable.