No, while Germany has not closed the border to Belgium like they did with France, Denmark, Luxemburg, Austria and Switzerland the border is not open to non-essential travel and border controls are in place. The Belgian police will only let German citizens leave Belgium but not let them enter Belgium. This rule is in place until May 8th but I think the will extend it.

Traveling to Europe for is only allowed for EU, UK, Swiss, Lichtenstein, Norwegian, Iclandic citiziens or people having residence permit of are a family member of such a citizens. In addition the right of free movement within Schengen is mostly temporarily suspended. This rules is in place until May 15th. We have to see what will happen in the next week.