These symbols are used by a number of different cultural groups in Central Africa.
For the Luba, the three circles represent the Supreme Being, the Sun and the Moon. This combination of circles symbolizes the unfailing continuity of life. It is a common belief that ancient African cultures feared the elements, but in fact African peoples trusted in the continuity of nature, its unchanging cycle of seasons and the succession of day and night.
The second image symbolizes the union of all creatures, confirming that everything in the universe is connected. Ancient African peoples in particular felt a close affinity to nature.
The knot, according to the Yaka, is another expression of the unity between the world and all its creatures. In the Yaka culture, this symbol would be used to protect a person's home and land.