FIFO (First In, First Out) is a principle in which the securities with the oldest acquisition dates are sold first as soon as a sale takes place. If you have acquired securities in several tranches at different times and prices, and you sell some of them, the FIFO principle assumes that the securities acquired first will be sold first. This procedure complies with the principles of German withholding tax.
This means that the first securities you purchased in a given class will automatically be sold and settled first for tax purposes. The reported return on your position refers to the total position.
You can track the tax impact of each individual transaction in the relevant securities settlement.