How to extract distinct values from a column in a virtual table

Hi, 

I have a table, I need create a calculated column which will look for Entity information per employee per date and create a text string which combines the entity property information for each employee in that month. 

I have created a new column called Entity_combi, the problem is there are some duplicate values in the columns, e.g., the employee is assigned to two jobs in that month, both jobs sit in entity EMEA-BE, in this case, I want the value in Entity_combi to be the unique entity values, i.e., correct value shoudl be "EMEA-BE" instead of "EMEA-BE-EMEA-BE"

I can not use distinct () here because in my table, I have Index column which assigns a unique value to each line of data, I need to keep the index for follow up calculation. So I need some column calculation like the one below. This one doesn't work because I can't use a variable in Values() function. 

Entity_combi =

var table_=filter(all(entity_summarize),entity_summarize[employee name]=earlier(entity_summarize[employee name])&& entity_summarize[Date Key]=earlier(entity_summarize[Date Key]))

var table2_=values(table_[Entity])

return

CONCATENATEX(table2_,entity_summarize[Entity],"-",entity_summarize[Index],ASC)