I want to post on a group and don't want anyone who checks my profile to see this post/comment except if he/she is in the same group.
Is that possible? And if yes, how?
I use the same type of group for my Fraternity's page on Facebook. We need to let members know information that is going on, and some of which can't be seen by others (especially uninitiated members :D).
The following is a screenshot a setting under "Edit Group" (you can get to this by going to the group page, then clicking on the button at the top right of your page).
Click here to see.
What you need to do is either have a "Closed" or "Secret" group (which I currently have my group set at).
This is typically used by businesses and things of that nature that want to get the word out that, for example, there will be a sale on Saturday or a special on beer. Anyone can see it and there are no restrictions.
This can be used by a business or an organization like what my fraternity is. Basically you are giving the people who are in the group access to the posts. BUT, different from "Secret" group, people can actually see the page in search (and can ask to be in the group).
As mentioned above, this type of page does NOT show up in search because the administrator only wants those people in the group to be able to see the posts. This goes great for a fraternity, because certain things such as ritual should be secret to only those initiated.
Basically how I see this, if you only want people in the group to see posts, you have the option of "Closed" or "Secret". From there you can answer the questions:
Hope this is helpful... if you have any other questions about groups you can go to facebook and they have many help and FAQ sections to help (I'm limited to two links in this post because I'm new).
The group you are posting in must be a Closed Group.
From here: https://www.facebook.com/help/privacy/groups