Assuming your Macro is replicating what you would do in the App (and it seems it is from your list of steps) you can set the path to a folder in an Open Dialog by making use of the Mac's inbuilt shortcut ⇧⌘G
When you are in any Open or Save dialog in an App, pressing ⇧⌘G brings up another dialog that allows you to enter the path to the folder you want.
Here is a link to a recent post explaining this in full:
Or (and this is what I do) you can use an excellent Keyboard Maestro plugin made by @noisneil which reduces all the steps to one Keyboard Maestro Action.