This is a must have for your Visual Studio 2017 and 2019. Multiple Solution Explorer Tools
This extension mainly makes scoped Solution Explore view (create by New Solution Explorer View in context menu in Solution Explorer) persistent across solution unload and load (ie. it saves state when Visual Studio shutdown and restores it when solution is opened next time). It allows you to rename solution explorer view so you can easily distinguish it.
It allows you to create multiple solution explorer windows, rename them AND best of all you can close Studio and re-open and it remembers your settings.