I can do so by changing the language I change the categories?
If I opened my Italian language classes Italian if I have the English language than English.

Hi Domenico,

Please have a look this documentation:
documentation.jomsocial.com/wiki/Translate_Elements

I hope can solving your problem

Regards,
Albert

I did not understand. I wish that when the language is in English the events page to show me only the categories for that country and not all the categories created.

Hi Domenico,

Do mean like this:
at Jomsocial backend, for event categories: A, B, C, D, E, F
and at frontend if language in English, the categories options will be: A, B, C. and if Italian language will be D, E, F.?

by default jomsocial can do that. if you want like that you must customize the event model:

/components/com_community/models/events.php:
line 514: public function getCategories($type = CEventHelper::PROFILE_TYPE, $catId = COMMUNITY_ALL_CATEGORIES)

how it changed? You can do the same thing for groups?

Hi Domenico,

I suggest you to hire developer for that. our support is limited for big changes/complicated.
I can't give you steps/instructions about that. Because need more than a day work for that (maybe 3 days) to build the code.

I hope you understand.

FYI: I you do any customization for this layer. it will lost then upgrade process

Regards,
Albert

ok thanks