Right, for example using the card plays you mentioned.
The player has a 5 card hand, including a coordinated attack and a guiding spirit. They play coordinated attack, laying it down next to the obstacle they are going to damage with it (handled later). Resolve the picking another runner and them drawing/playing.
Next, from your 4 card hand (since you played Coordinated Attack) you play Guiding spirit, putting it beside an obstacle like you did with Coordinated Attack, now the player has 3 cards in hand and, per Guiding Spirit, may discard them and draw a new hand (of 3 cards).
I think the confusion you might have had is that a played card, while not discarded yet until after the apply damage phase, are not still in your hand and may not be used to fuel other cards that require you to discard card(s).