The ISMEMBER() function can be used to show if the underlying stock is part of the selected index (S&P500, ASX200 for example) either currently, or at some time in the past.
NOTE: this function requires Optuma Symbol Lists to be enabled as part of your subscription.
In this example, ASH left the SPX in 2008, and AMZN has been in the index since 2005, using the following in a Show View:
This example is for the ASX200 using ISMEMBER(SYMBOLLIST=ASX 200), which shows KAR on the left being in the index from 2012 to 2016, and Z1P joining recently:
Backtesting historical index lists - survivorship bias-free data
The ISMEMBER() function can also be used to run tests on historical components of indices. See here for more information:
Survivorship Bias-Free Data