Planting in front of Field Maple

We live in the South Wales countryside & have an area in the garden that we are re designing.  There is a hedge of field maple between our garden & next door field & not too sure what shrubs we could plant in front of these?  The plot has partial sun & we have rotavated soil so not too bad, although a fair few roots from the surrounding trees.  We also plan to split the area into a rockery - where worst of roots are - & shrubs.  Any ideas for planting for the 2 areas to work together & best plants.  Many thanks