In Path of Exile, you can use multiple Timeless Jewels in your passive skill tree, but each jewel will have its own distinct effects and modifiers. It's important to note that the effects of Timeless Jewels do not stack with each other. Instead, they modify the passive skill tree based on their individual affixes, seed numbers, and placement.
When you place multiple Timeless Jewels in your passive skill tree, each jewel will have its own designated area of influence. The effects of each jewel will be limited to the passive nodes within its radius or specified area. These effects can include adding or modifying notable passives, altering values of nearby nodes, or changing node connections.
It's worth mentioning that the placement of Timeless Jewels becomes crucial when using multiple jewels. You need to carefully plan and consider the interaction between the jewel's effects, their respective radii, and how they fit into your overall build strategy.
By strategically placing multiple Timeless Jewels, you can create synergistic combinations that enhance specific areas of your passive skill tree or amplify certain playstyles. Experimentation and theorycrafting are key to finding the optimal placement and combinations of Timeless Jewels for your build.