If you are using the Ribbon interface - the feature is available on Process tab/Reverse Engineering group/XMI button.
If you prefer the menu interface you can change it this way: https://www.softwareideas.net/a/346/Ribbon-or-Classic-Menu
Then XMI import is available in File menu.
The simple way to access the features is also the quick access box (in the right top corner of the window) - type xmi and choose the first option: Process ->Reverse Engineering -> XMI.
I hope I helped you.