Out of game analysis is best, but if you're looking for in game alternatives.
In game damage meters such as Recount also track damage taken, deaths, dispells, absorbs, friendly fire, healing, over healing, energy gains and so on in addition to just damage. You can also review the last few pulls or overall data. You can also click on any of the items tracked for more detailed information such as clicking on damage taken will list off damage taken by source.
Out of game combat log parses like world of logs is better for analysis, but if you need a quicker in game reference a damage meter Recount will track that type of information.
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