Wisdom is an abstract thing, it is not a tangible good or commodity like gold, jewelry, money, etc. that can be hidden. For the very reason that wisdom is an abstract thing, you cannot tie nor hide it.
The proverb means that wisdom cannot be hidden; we can see wisdom all around us. The phones, the cars, the PCs, etc. we use are all expressions of wisdom.
In the community, some people abstain from alcohol, smoking, immorality, crime, etc. and they often live a long happy life – that is an expression of wisdom.
The good ideas, policies, plans, strategies, etc. that institutions, companies, communities, and countries set up to increase production, ensure financial independence, ensure development, etc. are expressions or examples of wisdom.
Wisdom is every where we turn our heads or turn our eyes to look.