Grouping Multiple Glyphs

I want to group multiple glyphs, for example (- – —), I have tried copying the kerning values from one to another from the kerning window but it doesn’t seem to be working?

Could someone help me with this, can you add a custom name to the glyph and group them that way, the same way you might group a capital (M N)?

Thanks,
Dan

Did you read this: https://glyphsapp.com/tutorials/kerning

What you need is class kerning.