How to check (in template) if user belongs to a group

Question

How to check in template whether user belongs to some group?

It is possible in a view which is generating the template but what if I want

Answer 1

Although the answer given by mishbah is right but it didn't work for me.

I am using Django 2.2.7 and i figured out that register = template.Library() should be replaced with from django.template.defaultfilters import register.

i hope someone will find it useful.