Eight persons- A, B, C, D, E, F, G and H are sitting around the square table. Four friends are sitting at the corner of the table facing inside the centre while the four persons are sitting in the middle side of the table facing outside the centre.
Two persons sit between C and F.
C sits third to the left of B.

A sits adjacent to B and immediate right of H.
A does not faces inside the centre.
Thus, Case 2 gets cancelled.

D sits second to the left of G.

Now, only E is remaining.

This is the final arrangement.
B sits third to the right of D.