The correct phrase is "I unwind in this group almost all the time."
In this context, "unwind" means to relax or relieve stress, and "in this group" suggests that the speaker feels comfortable and at ease within that social or activity group.
You can rephrase it in several ways, such as:
- "I relax with this group almost all the time."
- "I find myself unwinding in this group most of the time."
- "I feel relaxed in this group nearly all the