Question about trading a stock multiple times on the way up

I heard that some platforms give you the ability to choose which shares you want to sell.

For example, if I bought 100 shares of AMD at $95 and 50 more at $115, and say the current price is $102. I’d like to sell 50 shares of my $95 stocks for profit and buy back again if it dips later – while keeping $115 shares until they become profitable.

I’m using TD to trade and I don’t think i have this option.

Getting to my question… instead of holding all 150 shares and selling at $130, if I sold 50 at $102 then buy back 50 shares again at a lower price to ultimately sell all 150 shares at $130, am I still making profits from these intermediate trades?

At first I thought this was a straightforward question, and probably is, but I got confused as TD seems to pool all shares together for an average cost. Thanks in advance!