This skill is particularly applicable to team managers, but a large proportion of it is still applicable and useful for development, and especially project managers, who will be responsible for a project team.
As a new developer-cum-manager, this is likely to be the area where you have the least experience. So, it is vital that you acknowledge and analyze this, through the Johari Window, and build and use your support structure. Remember the impostor syndrome and consciously work to avoid it through open and honest dialogue with people whom you know well, as well as yourself!