PDFs of v_los, calculated from a 5D star’s path in action space (see Fig. 2). The thick black line total PDF shows the total density. This total can be decomposed into contributions from different groups, denoted by different colours. The probability that the star belongs to these different groups can be found by integrating the area under the respective lines, shown in the legend. As a star from the 6D sample, the true v_los is marked in green, and it is known that it is a GES member. Our method finds a 63% probability of belonging to GES but could also belong to Ungrouped Halo or Sequoia.