Hi, actually I can filter my contacts  using > menu >filter > then choose my single or multiple category ( depends on device, not all permits multiple choice). But,  when I close contacts I lost this "filter" , this selection.

But sometimes I receive request about a tips or function for hide a particular category. For example  private number , or "friends / school mate" if I use my devices also for work etcetc.

I think this function would be useful and appreciate by a group of users, and I suppose, the implementation non required a huge works

 Rather than a hide option, it would be great if your contacts could handle multiple address books at the same time. Then you could switch between these when you move between work and home. You could retain the ability to search all of your contacts and new messages would still show the sender details.

Welcome Pietro - I think this is a great suggestion and I can definitely see the need.

Biomehanika:

it would be great if your contacts could handle multiple address books at the same time

Yes - this would be great - I think many people would love to see this feature.

 It is a shame that you cannot put contacts into multiple catergories.