In many charts for Funk, Jazz or Rock tunes, you may see one chord symbol for an extended period, yet when you listen to a recording of the tune, you can hear the guitarist moving between several chords.
As long as you stick to the chord family (e.g., minor, or dominant) you can move freely between chords which have the same root as the basic chord symbol. The following guitar part could be played in a Funk tune over an Em chord symbol.
Here is an example of what a Funk player might do over an E7 chord symbol. This approach is best learned by a combination of experimenting, listening, transcribing parts, and playing with other musicians as often as possible. The more you do it, the easier it gets.