When we use the phrase "be/feel/look at home", we mean to be comfortable and relaxed in a particular setting or environment. There are many other ways to convey this feeling. One synonym for feeling at home could be feeling comfortable or at ease. Alternatively, feeling "in your element" means feeling comfortable and confident in a particular situation. Looking at home might refer to looking comfortable and familiar, for example, "he looked like he belonged". Another way to say this might be to appear natural or in their element. Regardless of the phrasing used, it's important to feel comfortable and at home in both our personal and professional lives.