Composite chart is calculated by taking the average longitudes of the same planet in the nativities of the members of the group; or as a midpoint by short arc between the same planets in the case of two individuals. MC is calculated in the same way, other cusps are derived from MC and average location.
Davison chart (known as relationship chart) is calculated for average time and location of individuals.
Coalescent charts are similar to composite charts except that they are based on harmonics rather than midpoints. They can be calculated only for two people.
The natal data for two persons should be set in Chart 1 and Chart 2. When a composite chart is created, double click the time bar to choose one of 3 types of composite chart, and to add the persons into the group. It is also possible to copy composite chart into Chart 1, and then study its compatibility with a person or a transit chart.