Component segment
You want to highlight a segment of a component, but always get the complete component highlighted if you click (M1) upon one of the segments?
Please release this button 
in the Pointer toolbar so that it looks that way: 
Now the Component is highlighted entirely only if you exactly hit the handle cross. For doing so this button 
needs to be activated.
Also the Context menu, to be reached by M2, offers an option to control the highlighting mechanism. Please use Option :