OWCS Engage clickstream tracking

Hi ,

We have created History Attribute and Definitions to track the user clicks on specific pages

The Segments defined are

1) if the user clicks on Pages A,B,C --> ABC segment

2)  if the user clicks Pages D,E,F --> DEF segment

if we click A->B->C Pages the visitor  are assigned ABC Segment but then i click on 4th page say E   and return to homepage my assigned  ABC segment is gone .

But we would like to keep  him in ABC segment until he is qualified to any other Segments

Can anybody help us what we are missing