Denmark, like every other country, is subject to some planetary boundaries. Using the FAO website, we can see that their main exports are food related, the top items being pork, cheese, bacon, food wastes, and pastries.

Their main imports are beef, pastries, wine, palm oil, and a few other food items.

Their total land area value is 4,309, and a little more than half (2,414) is used for crops, as seen on the AQUASTAT report on the FAO site. This means that their main exports are dependent on more than half of their land area. Looking at a chart of their fertilizer use, they utilize about 81 tonnes per 1000 ha for their crops, which is a lot when considering their main exports depend on their food production. They also use 1,497 tonnes per 1000 hectare of pesticides, which isn't terrible, but still harmful. So, two planetary boundaries concerning Denmark would be agricultural pollution and change in land use. Because they're so dependent on agriculture for their economy, they use fertilizers and pesticides to help maintain a steady stream of goods, which can be harmful to the environment in large quantities. Additionally, they're using a little over half their land for agriculture, which means there was a shift into that at some point in the past. This shifted the landscape, clearing out plant and animal species to make room for the production of food. These limitations could effect Denmark if their crop yield suddenly goes south, because a lot of their land is already used for their main investment.