IUPAC name of the following is

The longest carbon chain in this compound is a pentane as it contains five carbon atoms. The numbering is done from the carboxyl group $\left(-\mathrm{C}=\mathrm{O}\right)$ which is attached to the methyl group $\left(-{\mathrm{CH}}_3\right)$.

Now, there are two $\left(-\mathrm{C}=\mathrm{O}\right)$ groups (i.e. carboxylic acid) present, one attached at ${\mathrm{C}}_1$ and the other at $C_5$.

There are two methyl groups $\left(-{\mathrm{CH}}_3\right)$ attached to the carbon atom at position 3.

Hence, the IUPAC name is 2-(1-Methylpropyl)-1,5-pentane dioic acid.