Cast Between Different Slate Classes

Use StaticCastSharedPtr.

Example:

TSharedPtr<SWidget> Parent = GetParentWidget();
TSharedPtr<SSH_TEX_ToolBase> ToolBase = StaticCastSharedPtr<SSH_TEX_ToolBase>(Parent);

Make sure to check ToolBase.IsValid() before using like a nullptr check!

Reference

How to cast Slate widgets in Unreal EngineGeorgy's Tech Blog