Hi Divya,
In general there are for sure technically doable ways of achieving a resizable navigator also with the current version of the Cumulocity Web SDK.
This is however nothing that we support from a product perspective. So you are on your own in finding a solution for this.
Here are some hints:
In the end you would need to adapt the navigator width via styling, to do this with a hardcoded width was described here: Increase navigator width
You would need to define a CSS variable for the @navigatorWidth less variable.
Once you have that, you would need to add an element to interact with, which would then adjust the newly defined CSS variable dynamically.
Regards,
Tristan