Meaning of "offer their expertise leading expeditions"

Context:

They gather to swap and share books, yarn for crocheting, offer their
expertise leading mushroom and foraging expeditions, pass along
clothing and recipes, teach cooking classes, gather for fruit-gleaning
outings, organize free “shops” stocked with Halloween costumes and
holiday gifts.

Should the phrase "offer their expertise leading mushroom and foraging expeditions" be understood as:

They offer their professional knowledge in leading mushroom and foraging expeditions.

or:

They offer their expertise as they lead mushroom and foraging expeditions?

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Thank you.