There are no direct equivalents to this in the Thinkorswim language. There is a group of functions listed under the "Portfolio" section of the language reference. However those functions do not work at all within a custom watchlist column. This means only the built-in columns included on the platform are available for metrics related to your account positions.
- Average Trade Price
- P/L Day
- P/L Open
- P/L Percent
- P/L Year
- Position Net Liq
- Position QTY
Some of these may display overall account metrics while others may provide details specific to each ticker symbol in the watchlist.