I have some features in one part that have inside one of them, some relations.
Now in an assembly, I copied and made the paste special, the same features to other part. after having made the advanced reference configuration, and all the features pasted to the new part, I visited the relation to the corresponding extrude, and there wasn't any relations inside.
My question is, how can i copy those features, and bring the needed relations to the other part, without losing the relations?
I think what you are asking for is not possible in Creo Parametric.
in your relations there are dimensions involved. When you copy a function from part1 to part2 with paste special, the dimensions in part2 will not have the same reference:
In my example I copied the cylinder, in part1 the radius is d16 and in part2 the radius of the cylinder pasted changed to d15...
Have you looked at UDFs (User Defined Features)? That might be the functionality you're looking for. You can get feature-level relations in these. Search for "Creo UDF" at YouTube and you'll find a lot of examples and tutorials.
Yeah, if it's not the same or similar thing each time, UDFs could take a bit of time. You might be able to speed up the process using mapkeys, though. Select the features, Mapkey makes it a UDF and pauses, you switch model and resume the mapkey, mapkey inserts the recently saved UDF. If you use the same filename each time, that entire process might be amenable to automatization, though I haven't tried it myself. If you do it as a one-off, you don't need to bother with creating prompts and such.
Also, if you're copying and pasting similar, but not identical, things, there are some really clever tricks you can use with UDFs, using measurement features that collect information from the model and adapts the UDF depending on the results.