The graph does not clearly denote any asymptotes; therefore, it will be supposed that the function does not have any asymptotic behavior.
The graph can be divided into 3 segments divided by 2 hollow dots.
The domain of the first portion (extreme left) is

Similarly, in the case of the central segment,
[tex]D_2=\mleft\lbrace x\in\R|-2Finally, as for the third portion (extreme right)[tex]D_3=\mleft\lbrace x\in\R|6