Our woodland is mixed chestnut and hazel. They grow very well together for timber harvest, but not well for nuts.
Chestnuts need to grow to maturity to set a good nut crop, at which point they create a dense canopy and lots of shade. The hazel doesn't do well under shade.
Here our woods are traditionally managed with coppicing, which prevents a fully
closed canopy and limits the number of mature
trees.
If I were planning a nut grove as you describe, I would plan for comparatively few chestnuts, with large spacing. You want to aim for 30% or less canopy coverage, for the hazel to thrive. You can plant a bit more densely initially, and then thin any chestnuts that are doing less well.
Hazel does well at a dense planting. Stools close together strive for the light, and produce a secondary product of nice straight poles for us in the garden. Hazel needs to be coppiced periodically down to ground level. This prolongs the lifespan of the whole plant. If they are not coppiced, the whole stool tends to collapse apart under the weight of the timber. If you are planting a sufficiently large area, you could coppice 1/3 every 5 years or so, so that you always have some regenerating, some fruiting, and some maturing.
Make sure you look into varieties that are known to set good nuts in your region. Our climate here in the southern UK is marginal for chestnuts, which prefer warmer climates with longer growing seasons. Probably one year in 3 we get a good yield of nuts. In other years autumn closes in before the nuts have matured to a worthwhile size to collect.
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