If you could have a dynamic drop-down in the "Segments" area above the
report, which is populated by the values within a dimension, then a user
could select a value from the drop-down and the report would
automatically update based on that dimension. Ideally you would have
multiple drop-downs so that a user can easily filter by e.g. device
type, country, operating system etc without having to understand and
manipulate the dimensions from the side panel.